Metallurgical device



April 19, 1.932.

w. J. CHAPIN METALLURGICAL DEVICE Filed May 26, 1930 s Sheets-Sheet i fzwerzfzji% William J 6/20/ 72,

April 19, 1932. w. J. CHAPIN 1,854,179

METALLURGICAL DEVICE- Filed May 26, 1930 3 Sheets-Sheet 2 April 19, 1932. w. J. CHAPIN METALLURGICAL DEVICE Filed May 26, 1930 3 Sheets-Sheet 5 Patented Apr. 19, 1932 UNITE STATES WILLIAM J. CHAIPIN, OF CHICAGO, ILLINOIS, ASSIGNOR T0. CHICAGO STEEL FOUNDRY COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS METALLURGICAL DEVICE Application filed. May 26, 1930. Serial No. 455,630.

5 is to provide a heat treatment apparatus which will permit more eflicient-carburizing of small *metallic objects.

A' 'still further object'of the present inventionis-to provide a heat treatment apparatus floor fixture which will enable selective carbur'izing for large gears and all-over carburizing for small gears. Other-objects will appear during the course ofthe following specification.

In'a preferredembodiment of the invention, the heat treatment'fixtureor apparatus is built up of a hollow central post upon which is-supported a series'oibaskets or discs. The post cooperates with these baskets or n discs to form a seriesofsectional containers which are adapted to hold or support the articles being "heat treated or carburized. Suitable openings are formed in the central post and in the bottoms and/or walls of the container-sections so that the treating gases may readily pass through andaroundthe mass in most'satisfactorymanner. Two specific embodiments, to which the invention is by no means restricted, are shown in the accompanying drawings.

In the drawings:

Fig. 1 is a side sectional view of one form of the apparatus, while Fig. 2 is a top view and Fig. 3 isa top sectional view on the line 33 of the same form;

Fig. 4 is aside sectional view taken along the line 44 of Fig. 5', and'shows another form of apparatus which may be satisfac- 50 torily utilized; I

Fig. 5 is a top view of the device shown in Fig. 4;

Fig. 6 shows a hook for lifting my metallurgical device;

Figs. 7,8 and 9 represent on reduced-scale various component parts of'the embodiment shown in Figs. 1, 2 and 3; and

Figs. 10, 11, 12, 13, 14, 15, 16 and 17 represent on reduced scale the component portions of the assembled structure shown in Figs. 4 and 5.

In the embodiment shown in Figs. 1 to 3 and 6 to 9 the hollow central post is provided with a lower flange 31 and with several cylindrical portions 32 and 33, which de- 65 crease in diameter, the farther they are from the base flange 31. Attached to the outside of these cylindrical portions 32 and 33 are I the fins or vanes 34 and 35. As shown in the present embodiment of the invention, the'fins onthe uppermost section stop short'of the top ofthe post 30. In the arrangement illustrated, there are only two cylindrical portions 33 and 34, but it is obvious, of course, that additional cylindrical portions of varying di- 75 ameter'and height may also be employed. The fins 34 and 35'serve to correctly position the containers or discs which are supported upon the post 30, as will be later apparent. In the walls of the cylindrical portions 32 80 and 33 are a large number of holes 36 which serve to permit the passage of gases in and out of the central hollow post 30. Making the central'post'hollow not only serves to decrease the weight of the apparatus but in addition serves to increase the "circulation of gases through the same.

Adapted to be supported on the hollow post 9 are the supporting discs or spiders 40 and 41. The ring 40 is preferably positioned upon the flange 31 and the diameter of its central opening 42 is such that it will just clear the fins 34. The surfaces 43 of the ring or spider 40 are adapted to contact with the upper surfaces of the flange 31, while the vertical surfaces 44 are adapted to contact with the vertical edges of the flange 31. The plate 40 is provided with openings 45 which enable the hot treating gases to pass therethrough. These openings are arranged around the outside of the plate in the manner shown in Figs. 2 and 3. The recess 46 upon the upper side of the plate is adapted to support the sheet alloy cylinder 47 (see particularly Fig. l).

The upper ring or spider 41 is adapted to be placed upon the post 30 at the shoulder 50. This shoulder marks the place of jointure of the cylindrical portions 32 and 33. The downwardly projecting fins 51 rest upon the shoulders 52 between the vanes 34 and 35, as is apparent upon Fig. 1. The outer edge 53 of these fins 51 just fits within the alloy cylinder 47. The spider or disc 41 is provided with a series of openings (see especially Fig. 2) which permit the passage of gases from the lower compartment into the upper compartment. Resting upon the upper surface of the ring 41 is the alloy sheet cylinder 54, which is held in position by means of the rib 55. As mentioned before, only two sections or compartments are shown, but it is obvious that many more may be made by extending the hollow central post 30.

Fig. 6 shows a lifting hook 65, the lower portion of which is adapted to fit within the large opening 66 in the top of the central post 30. By means of this hook, the entire apparatus may be lifted out of the container or sheet alloy cylinder 67 with a minimum of inconvenience.

The carburizing gases enter through the opening 68 in the lower part of the casing 67 and pass through the apparatus in an evident manner. In Fig. 1 the cross-hatching 7 0 indicates the manner in which large gears may be positioned in the present invention for treatment. The apparatus is of such dimension that the outside diameter of the cylinder 47 will be slightly smaller than the opening in the gear. The cross-hatching 70 is represented in the space which is occupied by the gears. The inside compartments may be more or less completely filled with small gears or other small metallic objects.

This arrangement is particuarly advantageous since the gears positioned in the space 70 are hardened on the outside only. As a result the teeth are hardened while the backs of the gear remain soft, since no carburizmg gas has access to this portion of the gear structure. In this manner the manufacturer may harden the outside or teeth of his gears first and afterwards machine the inside to perfect dimensions. A subsequent machining of this character is frequently necessary. Otherwise gears which are hardened after machining frequently are distorted when Subjected to heat treatment and as a result have to be pressed into accurate dimensions after the heat treatment. This is an additional operation which increases the expense and difficulty of manufacturing the gears. Qr on the other hand they have to be held rigidly in special fixtures while quenching in order to prevent distortion. Summarizing, the embodiment shown in Figs. 1, 2 and 3 enables a combination of selective carburizing for large gears and all-over carburizing for small gears.

Figs. 4, 5 and 10 to 17 show a modified construction which may also be utilized. This construction also has a central post which is open from top to bottom, and the sides of which are perforated by a series of longitudinal vertical openings 81. In this construction the compartments are formed by a series of superimposed baskets 82, the central openings 83 in the bottoms of which t over the post 80. Both the bottom and sides of these baskets are provided with a large number of openings 84 which permit the ready passage of carburizing gases from one basket to another. Around the upper inner and upper sides of the walls of the backcts are a series of projecting ears 85 which enable the lifting spider shown in Fig. 10 to be utilized to lift the baskets from the assembly shown in Figs. 4 and 5. The

lifting spider is provided with a series of,

hooks 86 which fit into the openings in the projecting cars 85. The baskets are separated by means of the sleeves 87, the inside diameter of which is sufliciently large that they may be placed upon the central post 80.-

These sleeves are also provided with openings 88 which should preferably correspond with the openings 81 in the central post 80, so as to permit a passage of the carburizing gases. The assembled construction may be placed within the container 89 (see Fig. 4).

It is obvious that many changes may be made in the construction of the fixture shown, and it is intended that all such changes be within the scope of the present;

invention. The number of compartments may be varied, the manner of constructing the component parts may be changed, and the various component parts may be combined or further subdivided. In both em bodiments shown, very excellent circulation of carburizing gas is obtained to insure thorough treatment. When it is desired to treat articles for different lengths of time, some longer than others, an apparatus of the char-;

acter shown in Figs. 4 and 5 may be utilized, since one basket may be removed at a time. If it is desirable to subject all articles to treatment for the same length of time, the

apparatus shown in Figs. 1, 2 and 3 is more.

satisfactory, since the whole fixture may be removed from the carburizing enclosure at one time. The types of enclosures 67 and 89 shown are merely suggestive and diagrammatic, and do not represent the actual type of easing which is utilized in carrying the present invention into practice.

What is claimed is:

1. A heat treating fixture comprising a central hollow post, a series of compartments supported upon said post and a series of openings in said post and in said compartments adapted to permit the ready passage of hot carburizing gas through the fixture.

2. A heat treating fixture comprising a central hollow post provided with a large number of openings, a series of superimposed cylindrical compartments supported on said post, openings in the bottoms of said compartments so as to permit hot gases to pass in and out of said compartments and from one compartment to another, and means for supporting on the outside of said cylindrical compartments a series of superimposed gears.

3. In a device of the type described, a central perforated post, a perforated base member supported by said post, and a cylindrical casing supported on said base.

4. In a device of the type described, in combination, an outer casing having a gas inlet in the lower portion thereof, a central post removably positioned within said casing, a perforated base member supported by said post, and an inner casing supported on said base and spaced from said outer casing.

5. In a device of the type described, in combination, an outer casing having a gas inlet opening therein, a perforated base member positioned within said outer casing, and an inner casing supported on said base and removable from said outer casing, said inner casing being spaced from said outer casing.

6. In a device of the type described, in combination, an outer casing, a ring gear rack removably positioned within said casing, and. means for protecting the inner faces of gears placed on said rack from hot gases passing through said casing.

In testimony whereof I have subscribed my name to the foregoing specification and claims.

WILLIAM J. GHAPIN. 

